Vortex generator arrangement, flow control system and method for controlling a flow on a rudder surface

Abstract

A vortex generator arrangement for an aircraft comprising a surface section forming a flow surface interacting with a flow surrounding the aircraft in operation, wherein the surface section comprises an opening, a vortex generator movable between a retracted position and an extended position, a retainer for holding the vortex generator in the retracted position, a biasing structure for biasing the vortex generator towards the extended position and a release for releasing the vortex generator from the retainer such that the vortex generator can be moved towards the extended position. Further, a sealing membrane is provided completely sealing the opening when the vortex generator is in the retracted position. The vortex generator is movable through the membrane from the retracted position to the extended position. Furthermore, a flow control system, an aircraft and a method of controlling flow are described and claimed.

The invention claimed is: 
     
       1. A vortex generator arrangement for an aircraft comprising:
 a surface section forming a flow surface interacting with a flow surrounding the aircraft in operation, wherein the surface section comprises an opening; 
 a vortex generator movable between a retracted position and an extended position, wherein in the extended position the vortex generator extends through the opening into the flow and wherein in the retracted position the vortex generator does not extend through the opening into the flow; 
 a retainer for holding the vortex generator in the retracted position; 
 a biasing structure for biasing the vortex generator towards the extended position; 
 a release for releasing the vortex generator from the retainer such that the vortex generator can be moved towards the extended position; 
 a sealer completely sealing the opening when the vortex generator is in the retracted position; and 
 wherein the sealer is adapted such that the vortex generator can permanently destroy the sealing of the opening by the sealer when moving from the retracted position to the extended position by being configured to cut the sealer in two or more pieces. 
 
     
     
       2. The vortex generator arrangement according to  claim 1 , wherein the sealer is destroyable by the vortex generator when the vortex generator moves from the retracted position to the extended position. 
     
     
       3. The vortex generator arrangement according to  claim 1 , wherein the sealer is a sealing membrane. 
     
     
       4. The vortex generator arrangement according to  claim 1 , wherein the biasing structure is in a form of a spring. 
     
     
       5. The vortex generator arrangement according to  claim 1 , wherein the retainer is formed by a pin,
 wherein the pin is adapted to prevent movement of vortex generator from the retracted position to the extended position when the pin is in a first position, and 
 wherein the pin is movable from the first position to a second position by release for releasing the vortex generator from the retainer, wherein in the second position the pin does not prevent movement of the vortex generator from the retracted position to the extended position. 
 
     
     
       6. The vortex generator arrangement according to  claim 1 , wherein the retainer is formed by a strap or a wire, and
 wherein the release is provided in form of a pyrotechnic cutter adapted for cutting the strap or the wire for releasing the vortex generator from the retainer. 
 
     
     
       7. The vortex generator arrangement according to  claim 1  comprising a housing, wherein the surface section and/or the sealer form an outer surface of the housing and wherein the vortex generator, the biasing structure, the retainer and the release are arranged inside the housing. 
     
     
       8. A flow control system comprising a vertical tail plane for an aircraft and a control unit,
 wherein the vertical tail plane comprises a vertical stabilizer, at least one rudder surface and a plurality of vortex generator arrangements, wherein the at least one rudder surface is deflectable about a rudder axis with respect to the vertical stabilizer and wherein the plurality of vortex generator arrangements is arranged on the vertical stabilizer and along the rudder axis, and 
 wherein the control unit is adapted for actuating release of the plurality of vortex generator arrangements such that the vortex generator of the plurality of vortex generator arrangements move from their retracted positions to their extended positions, wherein the control unit is adapted to only actuate the release when a deflection of the rudder surface about the rudder axis exceeds a predetermined value, 
 each of the vortex generator arrangements comprising: 
 a surface section forming a flow surface interacting with a flow surrounding the aircraft in operation, wherein the surface section comprises an opening; 
 a vortex generator movable between a retracted position and an extended position, wherein in the extended position the vortex generator extends through the opening into the flow and wherein in the retracted position the vortex generator does not extend through the opening into the flow; 
 a retainer for holding the vortex generator in the retracted position; 
 a biasing structure for biasing the vortex generator towards the extended position; 
 a release for releasing the vortex generator from the retainer such that the vortex generator can be moved towards the extended position; 
 a sealer completely sealing the opening when the vortex generator is in the retracted position; and 
 wherein the sealer is adapted such that the vortex generator can permanently destroy the sealing of the opening by the sealer when moving from the retracted position to the extended position by being configured to cut the sealer in two or more pieces. 
 
     
     
       9. The flow control system according to  claim 8 , wherein the control unit is further adapted to only actuate the release when it has been detected that a maximum available yawing moment is required. 
     
     
       10. An aircraft comprising a flow control system according to  claim 8 . 
     
     
       11. A method of controlling a flow on a rudder surface of an aircraft comprising a vertical tail plane, wherein the vertical tail plane comprises a vertical stabilizer, at least one rudder surface and a plurality of vortex generator arrangements that each comprise:
 a surface section forming a flow surface interacting with a flow surrounding the aircraft in operation, wherein the surface section comprises an opening; 
 a vortex generator movable between a retracted position and an extended position, wherein in the extended position the vortex generator extends through the opening into the flow and wherein in the retracted position the vortex generator does not extend through the opening into the flow, 
 a retainer for holding the vortex generator in the retracted position; 
 a biasing structure for biasing the vortex generator towards the extended position; 
 a release for releasing the vortex generator from the retainer such that the vortex generator can be moved towards the extended position; 
 a sealer completely sealing the opening when the vortex generator is in the retracted position; and 
 wherein the sealer is adapted such that the vortex generator can permanently destroy the sealing of the opening by the sealer when moving from the retracted position to the extended position by being configured to cut the sealer in two or more pieces; 
 wherein the method comprises deflecting at least one rudder surface about a rudder axis with respect to the vertical stabilizer and wherein the plurality of vortex generator arrangements is arranged on the vertical stabilizer and along the rudder axis; and 
 wherein the method comprises actuating the release of the plurality of vortex generator arrangements such that the vortex generators of the plurality of vortex generator arrangements move from their retracted positions to their extended positions only when a deflection of the at least one rudder surface is detected that exceeds a predetermined value. 
 
     
     
       12. The method according to  claim 11 , wherein the releases are further only actuated when it has been detected that a maximum available yawing moment is required.